Cultures of smooth muscle cells will be derived from rhesus monkey throacic aorta and analyzed for Type IV and Type V (AB) procollagens and collagen. Sufficient numbers of smooth muscle cells will be grown to isolate enough of these collagens for biochemical characterizations such as amino acid analysis, preparation of cyanogen bromide peptides etc. Type IV and Type V collagens will also be isolated from bovine and human aortic media, human atherosclerotic plaques and the adult chicken gizzard. Attempts will be made to isolate these collagens as native molecules and to determine the chain composition of each molecule. The possible existance of isotypes for each of these collagens will be investigated.